Difference between revisions of "Hexagonal (or Trigonal) System"
Jump to navigation
Jump to search
(started article) |
|||
| Line 5: | Line 5: | ||
=Sources= | =Sources= | ||
*Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) | *Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) | ||
| + | [[category:geometry]] | ||
Revision as of 07:35, April 27, 2007
Four axes of symmetry: three, of equal length, lie in a plane at 120°; the fourth axis is longer or shorter and is at right angles to the others.
Crystals are generally prismatic or columnar, with rounded triangular or hexagonal cross section; characteristic forms are three- or six-sided prisms, pyramids, and rhombohedrons. The very similar trigonal system is often included within the hexagonal system. Chesterman, pp. 33-34
Sources
- Chesterman, Charles W. The Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf: New York (1987)